Injecting Routes into BGP

Injecting Routes into BGP
There are a couple of different ways to inject routes into BGP for advertisement:
 You could redistribute the IGP into BGP. Redistribution is the process of injecting the routing
information known by one routing protocol into another routing protocol.
 You can manually configure the routes for BGP to advertise.
Each of these ways of injecting routes will work equally successfully. Making the decision
on which form to use depends on the number of routes you want to inject into BGP. If you
want to inject only a few routes into BGP, your best choice would be to manually configure
BGP with the routes to advertise. On the other hand, if you want BGP to advertise numerous
routes contained in your IGP, you need to redistribute the IGP into BGP. The preferred
method of injecting routes into BGP is through manual configuration and not through redistribution.
The reason is if you have a route that flaps, that is, appears and then disappears
continuously, routers on the Internet will penalize that route and the route could get dampened
or temporarily removed from their routing tables.
Let’s look at how to configure each of these different forms of injecting routes into BGP.